Sarah Quinnell recently wrote a post on the LSE impact blog, following up on her Guardian post that "[blogs are increasingly recognised as a legitimate academic output". I want to consider some of the problems here, but not from the perspective of content. As people who've read any of my work on scholarly communication will know, I don't think there is necessarily a qualitative difference between the output mediums. So, let's assume that, editorially, I think it is *possible* for blogs to have the same standard of output as a journal (even if, in the majority of cases, they don't). However, blogs are transient, ephemeral, unarchived and present a problem for citation not, as Sarah makes out, because they would be placed at the lowest end of an impact hierarchy, but rather because of the mechanisms through which knowledge is constructed.

The sciences and humanities, although often portrayed as irreconcilable, actually both operate on a model of intersubjective consensus. Although the Hums. are weaker in this regard, the eventual aim is to achieve some form of less-contested consensus on the object of study. Science picks up as a better example here though for how scholarly communications play a role. When I say I "know" something, often, now, the mathematics and physics behind such knowledge could be seen as an act of faith: I cannot myself verify the findings, so I believe the word of science and simply say "I know". Now, the difference between science and religion here is the notion that, if I so wanted, I could become educated enough to understand how it works. I would achieve this by following the trail of what others have written, back from the most recent, through to the earlier papers upon which the more recent ones have based their assumptions. In this way, the history of a truth comes to light and can be verified, ideally back to the reality on which it is based, and that knowledge then amounts to more than faith.

Let us assume, now, though, that a crucial part of that chain is broken. At some point, one of the findings was published online, a blog or even just a website, that now no longer exists. There's a problem, obviously. At present, the mechanisms for digital preservation are not sufficient to merit blogs being cited as full-blown academic research. There are, however, ways this could be fixed: if authors were willing to assign DOI numbers, with all the obligations that a contract with CrossRef regarding preservation entails, then, and perhaps only then, would the medium have a fighting chance. In the meantime, although I think blogs are the foremost means for academic public engagement, I'm afraid that my faith remains with those who preserve material in a way that makes it knowledge, not theology.